1. Field of the Invention
This invention relates generally to gas masks and more particularly, the present invention relates to the provision of improved methods of securing components to the base facepiece of a gas mask. Thus, the present invention is directed to a combination of all elements that cooperate to provide a complete gas mask system as fabricated by the method disclosed.
2. Description of Related Art
Gas masks are well known in the prior art and have been improved over the years by many ingenious innovations marked by fresh and unusual approaches. While presently available gas masks can and do operate in the environments for which they were contrived, communication by voice has been difficult, leaks have appeared in the masks, components have not been firmly secured to the facepieces, and among other things, the devices have not been tamper proof. Many different innovative devices have been employed in the attempts to solve the problems presented. Some of these have either generated new problems or only partially solved the current problems, or both. Many of these conventional devices have thus met special needs as presented by specific difficulties and have, therefore, served narrow purposes. Some of these prior art devices, among other disadvantages, have been unreliable and unpredictable in operation under continued use and have been expensive and complicated to manufacture. Prior art patents that were brought to the attention of the applicant through a novelty search conducted in the United States Patent and Trademark Office have been described in what immediately follows.
The prior art includes:
U.S. Pat. No. 2,164,330, issued Jul. 4, 1939, to S. H. Katz et al. for FULLY MOLDED GAS MASK FACEPIECE. In addition to fabrication by a method of molding, the device provided for prevention of condensation on the lenses and thus alleviated impaired vision due to breath condensation. Improved voice transmission through the faceplate was also accomplished.
U.S. Pat. No. 3,181,531, issued May 4, 1965, to A. Angioletti for RUBBER GAS MASK. Weight reduction through single piece molding along with the means for inhalation and exhalation were the main thrusts of the inventive device.
U.S. Pat. No. 3,220,408, issued Nov. 30, 1965 to C. G. Silverberg for FACE MASKS. The specific issues resulting from radioactive fallout were contemplated along with difficulties resulting from leaks about seals between the lenses, the other fittings and the body portion of the masks. The capability of cleaning the mask after use in a hostile environment was of major concern to the inventor.
U.S. Pat. No. 4,886,058, issued Dec. 12, 1989 to G. M. Brostrom et al. for FILTER ELEMENT. The patent taught a filter element to be attached directly to a face mask thus to become a part integral therewith. While not contemplating a total gas mask system, the patent mentions ultrasonic welding as a method of bonding.
U.S. Pat. No. 4,905,683, issued Mar. 6, 1990, to R. Cronjaeger for RESPIRATOR MASK FOR POSITIVE PRESSURE RESPIRATOR EQUIPMENT. This invention was concerned mainly with the prevention of the escape of respiratory gas of large oxygen content into the surrounding environment. A primary thrust, therefore, was directed to leak detection from the interior of the mask.
U.S. Pat. No. 4,926,853, issued May 22, 1990, to P. P. Meunier for GAS MASK NOSE OCCLUDER. This innovative device described an in-mask means for occluding the nostrils of a user so as to perform what the inventor referred to as the valsalva manoeuvre. This, it is explained, is to be used to equilibrate the internal air pressure in the sinus cavities and ears with the atmospheric pressure. In operation, internal prong members allow a user to pinch the nostrils together so as to accomplish the equilibration.
U.S. Pat. No. 4,960,121, issued Oct. 2, 1990 to J. E. Nelson et al. for HALF-FACE MASK ASSEMBLY. This patent teaches a novel head harness as a primary thrust and interchangeable face seals for use with different sized faces. Claimed as a primary advantage is the easy donning and doffing of the apparatus. Ultrasonic welding is mentioned as a means to join connectors to a hard shell.
U.S. Pat. No. 4,961,420, issued Oct. 9, 1990 to G. Cappa et al. for GAS MASK FOR OPERATION IN CONTAMINATED AREAS. The inventive device described contemplates the problems involved with inhalation and exhalation; voice communication from a user to others; and the capability to receive drink and nourishing liquids without removing the mask, among other things.
U.S. Pat. No. 5,630,412, issued May 20, 1997, to A. Dubruille et al. for PROTECTIVE EQUIPMENT FOR THE HEAD COMPRISING A BREATHING MASK AND AN OPTICAL SCREEN. This innovative device has been described as primarily for use in aviation when loss of pressure is encountered and including connection to a source of breathing gas. It is adaptable for rapid application under emergency conditions.
These prior art devices are commendable and show a truly creative spirit for their times and intended applications. The inventors and their inventions have contributed remarkably to the technology involved. However, these prior art structures do not include those combined elements of the invention described and submitted herewith that provide greater facility of use, economy of fabrication, higher reliability and ingenious arrangement of components that make the instant invention the high culmination in the art of gas mask technology to date.
It would thus be a great advantage to the art to provide means for securing components to the base facepiece of the gas mask by means resistant to chemical attack when employed in environments containing substances capable of attacking conventional bonding agents, e.g., glues and cements such as are traditionally used in joining and bonding operations.
Another great advantage would be realized through the provision of a bonding method and resulting seal between components and the base face piece that is free of leaks, including powder and fluid leaks, both liquid and gaseous.
A further desirable advantage would be to provide an improved and convenient means of voice communication between users of the gas mask.
A still further beneficial advantage to users and manufacturers of gas masks would manifest itself in the provision of an improved grouping of components that would result in greater facility of fabrication, lower cost of manufacture and overall weight reduction.